“It's really important to us and for patients to know that these organisations are signed up to these values and principles", when they used the NHS logo, he told MPs on the Health Select Committee.

Under the Government’s reforms, the NHS Commissioning Board will take on responsibility for overseeing the health service. Part of its remit will be to buy in services, both from NHS and private providers.

Ms Plumb, has a degree in politics from Durham University, an MA in public policy from York University and a diploma in strategic marketing from the Chartered Institute of Marketing.

She has recently joined Twitter, the social networking site, on which she describes herself as “passionate about the NHS”. However, she has yet to ‘tweet’ a message.

Jamie Reed, the shadow health minister, said people would be “shocked” at news of the appointment, a day after the Royal College of Nursing announced 6,000 nursing jobs had been lost since the general election.

He said: “The Government has rashly forced parts of the NHS into the private sector and they’re now hiring staff to check who’s using the trusted NHS logo.

“The NHS frontline is taking a battering as thousands of jobs are axed and ministers should get a grip on that instead.”

Speaking after the hearing, Worsley and Eccles South MP Ms Keeley said Sir David had "failed in his attempt to defend the development of a unit to promote the NHS 'brand' to the public.

"The NHS is a service not a brand," she said.

"My constituents will be unhappy to see a salary of nearly £100,000 attached to this sort of unnecessary post.That money should be spent on patient services."

Tim Kelsey, the NHS national director for patients and information, said Ms Plumb would lead a team of customer relations executives who would ensure the board “never loses sight of its responsibility to patients”.

He said: “Their job will be to make sure patients and the public fully understand what the NHS can offer to them, by making sure the NHS communicates with them in ways which make sense to them and which they can access easily.

“The word ‘brand’ in the sense of this role, means the NHS’s identity and its commitment to patients.”

An NHS Commissioning Board spokesman said: “The NHS is changing and improving, and any organisation involved in patient care must understand and demonstrate the culture and values of the NHS as set out in the NHS Constitution, and treat our patients accordingly.

“We also have a duty to ensure our patients are never misled by inappropriate use of the NHS logo.”